The Seychelles butterflyfish (''Chaetodon madagaskariensis'') is a species of marine ray-finned fish, a

butterflyfish The butterflyfish are a group of conspicuous tropical marine fish of the family Chaetodontidae; the bannerfish and coralfish are also included in this group. The approximately 129 species in 12 genera are found mostly on the reefs of the Atlant ...

belonging to the family Chaetodontidae. It is found in the Indian Ocean from eastern Africa (as far south as

Port Elizabeth Gqeberha (), formerly Port Elizabeth and colloquially often referred to as P.E., is a major seaport and the most populous city in the Eastern Cape province of South Africa. It is the seat of the Nelson Mandela Bay Metropolitan Municipality, Sou ...

in South Africa) east to Cocos-Keeling Islands and Christmas Island, north to

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

. The Seychelles butterflyfish is found in areas of rich coral growth on seaward reefs, at 10–40 m depth. It grows to a maximum of 13 cm (more than 5 in) long. The body color is silver at the head, becoming white towards the tail, with a triangular orange patch covering the posterior and the caudal peduncle. There are a series of dark grey chevron lines on the sides of the body, partly broken into spots. Between the eyes and the start of the dorsal fin there is a black patch rimmed with white. The base of the caudal fin is white, followed by an orange patch and a white rim.

Systematics

The Seychelles butterflyfish was first formally described in 1923 by the

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...

zoologist Ernst Ahl (1898-1945) with the type locality given as Mauritius. The specific name is sometimes spelt ''madagascarensis'' but Ahl’s original should be used. ''C. madagaskariensis'' is one of the "crowned" butterflyfishes. These form a group of largely

allopatric Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...

species sharing the overall color pattern of dark forward-pointing chevrons on silvery hues, (usually) a black-and-white crown spot and yellow to red hindparts to a stunning degree; they differ in the exact combination of hues and some small pattern details. Other members of this lineage are the closely related Eritrean (''C. paucifasciatus'') and

atoll butterflyfish ''Chaetodon mertensii'', the atoll butterflyfish, yellowback butterflyfish or Merten's butterflyfish, is a species of marine ray finned fish, a butterflyfish belonging to the family Chaetodontidae. It is found in the western Pacific Ocean. Des ...

es (''C. mertensii''), and the more distant

pearlscale butterflyfish The pearlscale butterflyfish (''Chaetodon xanthurus''), also known as yellow-tailed butterflyfish, crosshatch butterflyfish or Philippines chevron butterflyfish is a species of marine ray-finned fish, a butterflyfish belonging to the family Chae ...

(''C. xanthurus''). The "crowned" ''Chaetodon'' are a clearly recognizable

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

, but their further relationships are otherwise less clear. They were often placed in the

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

''Exornator'', or considered a distinct subgenus ''Rhombochaetodon''. According to various

DNA sequence DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. Th ...

studies, some older and more singular lineages. These include species such as the

Asian butterflyfish ''Chaetodon argentatus'', the Asian butterflyfish, three band butterflyfish or black pearlscaled butterflyfish, is a species of marine ray-finned fish a butterflyfish belonging to the family Chaetodontidae. It is native to the western Pacific O ...

('' C. argentatus''), the

blue-striped butterflyfish The bluestripe butterflyfish or blue-striped butterflyfish (''Chaetodon fremblii'') is a species of butterflyfish (family Chaetodontidae) found in the waters surrounding the Hawaiian Islands. The fish is endemic to Hawaii where it is common on sha ...

('' C. fremblii'') and

Burgess' butterflyfish Burgess' butterflyfish (''Chaetodon burgessi''), also known as the black & white butterflyfish or black-barred butterflyfish, is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae. It occurs in the wester ...

('' C. burgessi''). ''C. burgessi'' is in fact so peculiar that it was placed in a monotypic subgenus ''Roaops''. But recognition of this would probably result in several other small or monotypic subgenera becoming justified, and the older ''Rhombochaetodon'' would be the more conveniently apply to the entire

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

. But the expanded group is of unclear relationships to species like the

speckled butterflyfish ''Chaetodon citrinellus'' is a species of butterflyfish (family Chaetodontidae). It is commonly known as the speckled butterflyfish or citron butterflyfish. It is found in the Indo-Pacific: the Red Sea, East Africa to the Hawaiian, Marquesan and ...

(''C. citrinellus'') and the four-spotted butterflyfish (''C. quadrimaculatus''). These might be members of the subgenus ''Exornator'' – the lineages around the

spot-banded butterflyfish The spot-banded butterflyfish or spotband butterflyfish (''Chaetodon punctatofasciatus'') is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae. It is from the western Pacific Ocean. It is found in the I ...

(''C. punctatofasciatus'') – and ''C. citrinellus'' certainly looks somewhat similar to these. Yet phylogenetically, their position towards ''Rhombochaetodon'' is unresolved, and ultimately it might be better to merge both ''Rhombochaetodon'' and ''Roaops'' in ''Exornator''. If the genus ''

Chaetodon ''Chaetodon'' is a tropical fish genus in the family Chaetodontidae. Like their relatives, they are known as "butterflyfish". This genus is by far the largest among the Chaetodontidae, with about 90 living species included here, though most migh ...

'' is split up, ''Exornator'' might become a subgenus of ''Lepidochaetodon'' or a separate genus.

References

External links

* {{Taxonbar, from=Q582693

Seychelles butterflyfish The Seychelles butterflyfish (''Chaetodon madagaskariensis'') is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae. It is found in the Indian Ocean from eastern Africa (as far south as Port Elizabeth in ...

Fauna of Seychelles Fish of the Indian Ocean Marine fauna of East Africa